Mitsue Sugimoto

In the field of mental health, the role of Experts by Experience (ExE) has been gaining increasing attention. However, theoretical research on this topic remains limited, leaving it unclear how ExE can contribute to improving psychiatric research and services. In this paper, I propose two explanations for the contributions of ExE, drawing on perspectives from feminist philosophy of science. The first explanation focuses on the epistemic capabilities of ExE, grounded in standpoint theory. This approach highlights the unique individual potential of ExE as a factor that enhances psychiatric research and services. The second explanation underscores the epistemic diversity between ExE and professionals in research and/or service contexts, focusing on the value of epistemic diversity within teams and communities. The main difference is that epistemic capabilities focus on the individual, while epistemic diversity focuses on the collective. I argue that these two explanatory models should be chosen based on research design, but in the context of psychiatric PPI, considering ExE participation not only in terms of standpoint but also in terms of epistemic diversity may suggest a more inclusive approach to PPI.